The invention pertains to the field of valved interconnected fluid couplings having frangible or "breakaway" connection means.
In the fluid handling arts, particularly in pressurized hydraulic systems, fluid couplings are employed to interconnect hose, pipes, conduits and tank mounted fittings, and the like. In some applications it is desired that, for safety reasons and to prevent extensive hose or conduit damage, the coupling halves disengage upon being subjected to predetermined axial or shear forces. Such operation is desirable, for instance, in the aircraft industry in fuel lines and other fluid lines to minimize fuel loss and fire hazard in the event of a crash.
Fluid couplings utilizing frangible connections employ valves adapted to close on disengagement of the coupling halves. Such valves may be biased by springs, and/or by the fluid within the associated hose or conduit, and are usually of the poppet, sliding or pivoted type. An example of such coupling is shown in U.S. Pat. No. 3,719,194 and in the assignee's application Ser. No. 441,242, filed Feb. 11, 1974.
One of the problems with known frangible connections for fluid couplings arises from the difficulty in assembling the coupling and maintaining close control over the forces necessary to separate the coupling bodies. As shown in U.S. Pat. No. 3,719,194, frangible connections usually take the form of defining a weakened portion in a connecting sleeve or utilize shear pins. Such structure is usually relatively bulky and distracts from the exterior coupling configuration if it is desired that the coupling be as concise in dimension as possible and having a smooth pleasing appearance free of handles, sharp edges and pin ends.
Further, known frangible couplings utilizing shear pins do not provide a uniform assembly pressure and resistance to coupling half separation throughout the periphery of the coupling, and known devices utilizing frangible connection means require a plurality of components resulting in high material and manufacturing costs.